Hydraulic brake for railway or tramway vehicles.



No. 659,517. Patenfed Oct. 9, I900.

I c. DUREY. HYDRAULIC BRAKE FOR RAILWAY AND TRAMWAY VEHICLES.

(Application filed' Nov. 9, 1899.)

5 Sheets-Sheet l.

(No Model.

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No. 659,5|7. Patented Oct. 9, I900.

v c. DUBEY.

HYDRAULIC BRAKE FOR RAILWAY AND TRAMWAY VEHI'CLES.

(Application filed Nov. 9, 1899.) (No Model.) 5 Sheets-Sheat 3.

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No. 659,5l7L Patented Oct. 9, I900.

C. DUREY. HYDRAULIC BRAKE FOR RAILWAY AND TRAIRWAY VEHICLES.

(Applicition filed Nov. 9, 1899.) (No Model.) 5 Shoats$hoat 4.

INVENTOE WITNESSES; M @JMQ ATTORNEYS N01 659,5. Patented Oct. 9, I900;

C. DUREY.

HYDRAULIC BRAKE FUR RAILWAY AND TRAMWAY VEHICLES.

A licatim :iieii ov. 9, 1899.) (No Model.) 5'S'haots--Sheet 5.

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rte STATES OAMILLE DUREY, OF PARIS, FRANCE.

HYDRAULIC BRAKE FOR RAILWAY OR TRAMWAY VEHICLES.

$PECIFIGATION forming part of Letters Patent No. 659,517, dated October 9, 1900.

Application filed November 9, 1899. 3eria1NOH736A17. (No model-l To all whom it may concern:

Be it known that I, CAMILLE DUREY, engineer, a citizen of the Republic of France, and a resident of 17 Rue Lebrun, Paris, France, have invented certain new and useful Improvements in Hydraulic Brakes for Railway or Tramway Vehicles, of which the following is a full, clear, and exact specification.

In the hydraulic brake which forms the object of the present invention th motive power for actuating-the gearing for operatingihe brake-blocks isentirely obtained from the momentum of the vehicle in movement at the precise moment when this action becomes necessary. The break-gear of each vehicle is connected with the plunger of a brake-cylinder communicating, on the one hand, with a reservoir of liquid in constant communication with the atmosphere, and, on the other hand, with a pump the plunger of which is connected with the axle of the vehicle by a crank and eccentric or by any other suitable means for transmitting movement. The suction of this pump communicates with the liquid-reservoir. During the movement of the vehicle the plunger of the pump constantly receives an alternating motion; but it produces the effective action of pressure of the liquid in the brake-cylinder only at the moment when it becomes necessary to actuate the brake. The body of the pump is for this object provided with an electrically-operated mechanism, which enables the action of compression of the pump to be started or stopped at will. The passage of the current into this mechanism causes an interruption of the action of the'pumpthat is to say, the brake ceases to actwhile the breaking of the circuit, on the contrary, causes the pump to come into action and the brake to be applied. By simply moving a switch connect ing or breaking the circuit it is possible to obtain all that is necessary for operating the brake. It will be readily seen that the brake will act automatically as soon as a cessation of current is produced accidentallyfor instance, in case of the snapping of a wagoncoupling or the like.

In the accompanying drawings, Figure l is a diagraminatical view of the whole installation for a railway-vehicle, each of the vehicles of a train having similar devices with the exception of the apparatus for electrically operating them, which is common to the whole as well as the source of electric energy. Fig. 2 is a longitudinal section of the pump 0. Fig. 3 is a plan view of said pump. Figs. 4, 5, and 6 are details of the brake-cylinder in longitudinal vertical section, longitudinal horizontal section, and transverse section, respectively.

In diagram Fig. 1, a indicates the brakecylinder, of which the plungerf is connected with the draw-bar. b is a reservoir of liquid open to the air and communicating by means of a pipe 3 with the cylinder (1. c isa pump, the body of which is connected on the one hand bya pipe 0 with the liquid-reservoir and on the other hand by a pipe 1' with the brake-cylinder. The plunger h of the pump is constantly set in motion by a crank-rod l, connected to an eccentric e, keyed on the axle d of the vehicle. Finally, by means of an electric switch t the following etfec't-s may be obtained by placing the said swilch in three difierent positions:

First. The taking oif of the brake. In this position the pump does not work-that is to say, the plunger of the pump in its alternatiug movement does not forceinto the brakecylinder, and consequently the plunger of the said cylinder is not actuated. The cylinder at this moment communicates with the reservoir,which avoids any unintentional application of the brake.

Second. The applying of the brake. In this position the pump actuates the plunger of the brake-cylinder, and the communication of this cylinder with the reservoir is interrupted.

Third. The staid qua. In this position the pump ceases to actuate the plunger of the brake-cylinder, while the communication between the said cylinder and the reservoirremains interrupted. With regard to the pres sure to be obtained by the pump the plunger should preferably be single-acting, with suction pipe and double force pump action, whereby a. more regular flow is obtained.

The body of the pump is composed of two parts 1 and 2. The front part 2 corresponds to the front part of the plunger. It is closed by means of a cap 3, which is screwed down on its bearing 4 against a recessed leather Washer 5, forming a joint on the rod of the plunger. An ajutage is formed at 6, allowing a chamber 7 to be connected with the reservoir by means of a small pipe, thus allowing anyliquid which may be introduced into said chamber to be discharged without exter- -nal loss.

8 is a stuffing-box gland. In the rear part a flange 9 and four bolts 10 enable the part 2 of the body of the pump to be screwed or pressed onto the part 1. A leather washer 11, pressed between the parts by this screwing, forms a joint on the plunger and separates the chambers in the front and rear of the plunger.

The enlargement 12 in the part1 of the body of the pump serves as a casing for two superimposed valves 13 and 14, the lifting of which places a chamber 15, and consequently the rear part of the body of the pump, in communication either with a chamber 16 when the valve 14 lifts or with a chamber 17 when the valve 13 lifts. The chamber 16 is in constant communication with the front part of the body of the pump by means of passages 18 and 19. It is also in communication with the brake cylinder by meansof a pipe 2', fixed on a nozzle or union 20. The chamber 17 is connected with the reservoir by a suction-pipe 0, tixed on a nozzle or union 21. The chambers 16 and 17 are further capable of directly communieating with each other by means of a series of passages 22, 23, 24, and 25. In the cylinder 24 a spring 26, capable of being regulated by a nut 27, is arranged to hold on its seat a ball 28 by means of a piston 29, perforated with holes. This ball plays the part of an adjustable safety-valve, allowing the liquid forced by the pump to communicate with the suction-chamber when the forcing-pressure exceeds the limit determined by the pressure of the spring 26. At the lower part of the enlargement 12 a bobbin 30 is screwed, serving as support for a solenoid. Under the action of an electric current the solenoid attracts, vertically, a cylinder 31, which encounters a rod 32 and carries it with it in its ascending movement. The rod 32, which is suitably guided, presses its upper end beneath the valve 13 and holds it open when it is raised for the-suction; The nipple of the valve 13 encounters the valve 14 and maintains this latter also open when it is raised in its turn.

33 is a block of soft iron having for its object to increase the attractive power of the electric solenoid on the movable mass 31. and to insure by contact the correct position of the latter in spite of jolts or vibration. In the difierential plunger the front and rear sections are between them as the numbers 1 and 2, this yielding the same output as the advance or return of the piston. As a matter of fact, when the piston sucksin while it ascends it delivers with its forward surface or front side, and the delivered liquid passes through the conduits 19 and 18 into the brakecylinder.

When the piston descends, the rear face delivers a volume of liquid which is twice as great as delivered by the front at the preceding travel. Half of this volume passes through the conduits 18 and 19 behind the front side of the piston. Consequently the pump works by simple suction and constant continuous delivery. The rod 7?. of the plunger is pivoted to a rod Z, receiving its movement from the axle d or the wheel of the vehicle by means of an eccentric e.

In order to reduce to a minimum the consum ption ofliquid under pressure with a view to a more rapid application of the brake, I construct the brake-cylinder, preferably,with a differential plunger. This plunger of peculiar construction moves in a cylindrical recessed body a, Figs. 4, 5, and 6. The extremity 34, which is provided with a leather washer 35 on the face which receives the action of the liquid, has a stud 36, sliding in a groove 37 of a sleeve 38, at the end of which is fixed a head f for actuating the brake-levers. In the interior of the sleeve 38 a spring 39 is arranged, which tends to constantly maintain the two ends 34 and f of the brakeplunger in their position of maximum separation. Two tubes 40 and 41 are placed within the spring in the axis of the cylinder. The tube 40, which is outside the tube 41, is closed at one of its ends, and the other end is fixed on the part 34 of the plunger. The tube 40 and the plunger 34 are therefore integral. The tube 41 is open at both ends and passes through the part 34 of the plunger with considerable friction and carries fixed at the end a screwed dowel 42. This dowel closes the endof the cylindrical body and forms a joint at 43 by being screwed up by a bronze box 44, which bears externally on the end of the cylindrical body, also forming a joint at 45. The box 44 places the interior of the tube 41 in communication with the piped, which pipe conveys the liquid forced by the pump to the brake-cylinder.

46 is a retaining-valve preventing the liquid returning from the cylinder to the pump. At the side of the cylindrical body, at the height of the internal wall at the end, another bronze box 47 is externally screwed. This box, Fig. 6, serves for the mounting of a valve 48, the lifting of which causes the central chamber 49, and consequently the rear chamber of the plunger of the brakecylinder, to communicate with a chamber 50, which is in constant communication with the reservoir by a pipe 5, fixedon a nozzle 51. The vertical wall of the box 47 is strengthened at 52 to enable a vertical passage 53, communicating with its lower end with the chamber 50, to be bored in the said wall. The box 47 is closed at its upper part by a head 54 of special form, fixed by means of bolts 55L In this head a cylindrical basin is formed having its axis horizontally arranged, which basin serves for supporting or holding the mechanism for closing a passage 56, placing the lower partof the head, and consequently the chamber 49, in communication with the interior of the basin. On the external wall of the bottom of the basin an electromagnet 57 is fixed, the cores of which pass through the bottom of the basin and are capable, under the action of an electric current, of attracting a piece of soft iron 58, normally held apart by an adjustable antagonistical spring 59. With the attraction of the armature 58 there is produced a corresponding oscillating movement of a lever 60, which lifts a ball-valve 61 and places the passage 56-that is to say, the pressure-chamberin communication with the interior of the basin-in other words, with the reservoir. A passage 62 places the interior of the basin in communication with the passage 53 when the head 54 is put in position. A screwed plug 63 closes the basin and allows it to be inspected. A valve 64, operated from the outside by means of a handwheel 65, is placed across the passage 53. Two passages 66, bored in the valveplug, enable at will the communication between the chamber 49 and the passage 53 to be closed or reestablished. This valve thus enables the brake to be taken off in the absence of electric current. This condition arises in shunting when a vehicle is separated from the train, and in consequence of which shunting the brake of the said vehicle has been applied automatically. This maneuver in no way intercepts the communication between the upper and lower parts of the passage 53, owing to passages 67 and 68 and an annular recess 69 around the valve-plug.

In a vertical plane passing through the axis of the cylindrical body a a chamber 70, Fig. 4, is bored in the thickness of the breechpiece, said chamber serving to receive a valve 71, held normally on its seat by a spring capable of being adjusted from the outside. The lifting of the valve places the rear chamber of the plunger 34 in communication, by means of passages 72, 73, and 74, with the front part of the tube 41 when the pressure in the tube attains a given amount. A passage 75 of very small diameter,bored in the plunger 34-, allows the liquid contained between the tubes 40 and 41 to be discharged.

The cylindrical bodyct is closed at its front end by a head 76, forming a joint at 77 and held by two bolts on corresponding flanges or lugs on the cylindrical body, While 78 is a stuffing-box.

The cylinder is provided laterally at 79, Fig. 5, with a passage connected with the reservoir by means of a pipe, thus allowing any external loss of liquid to be avoided. On the cylindrical sleeve 38 of the sleeve-plunger a ring 80 is arranged, which is formed in two parts brought together and pressed against the said sleeve by a spring 81. This ring serves for adjustment to allow for the Wear and tear of the brake-blocks.

In ordinary working by bringing the lever of the switch, Fig. 1, on the contact 82 a flow of the current arising from a suitable source of electricity to is introduced both in the electromagnet 30 of the pump and in the electromagnet 57 of the brake-cylinder. The result of this is that the valves 13 and 14 of the pump being raised the liquid drawn up by the pipe 0 is not forced into the brake-cylinder. On the other hand, in the brake-cylinder the lever is moved over, the ball-valve 61 is lifted from its seat, and communication is established between the chamber 49 and the pipe sthat is to say, between the rear face of the plunger and the reservoir. The brake is therefore taken off completely. By returning the lever of the switch to the contact 83 the passage of the current is interrupted both in the electromagnet 30 of the pump and in the electromagnet 57 of the brakecylinder. The result is that, on the one hand, the valves 13 and 14 of the pump being no longer held up the pump forces back through the pipe 2' the liquid drawn up from the reservoir by the pipe 0. On the other hand, the ball-valve 61 of the brake being pressed on its seat all communication between the chamber 49 and the pipe 8 is intercepted. The liquid forced back by the pump lifts the retaining-valve 46 and passes through the pipe 2' into the tube 41, and then acts on the end of the tube 40. The Whole plunger is thus moved forward, while the liquid acts only on a very small surface of the differential plunger. In fact, while the valve 71 remains closed-that is to say, so long as the pressure arising from the pump does not exceed the tension of the spring -the liquid of the pump does not reach the plunger 34. The latter being displaced draws up the liquid at the ordinary atmospheric pressure coming from the reservoir Z) and lifts the retainingvalve 48. The Valve 71 is regulated in such a way as to remain closed until the plunger of the brake-cylinder completes the necessary movement for bringing the brake-blocks in contact with the tires of the wheels. At this moment only a great effect is produced, because the contact being established, the valve 71 being raised, the liquid under pressure coming from the pump by the pipe z'flows by the passages 74,73, and 72 behind the plunge'r 34, while the retaining-valve 48 is closed. If the passage of the current be again established solely in the electromagnet 30 of the pump, the latter will cease to force liquid into the brake-cylinder; but as the liquid under pressure accumulated behind the plunger of the brake-cylinder is not capable of returning to the reservoir the pressure applied to the brake-blocks will be maintained, and this is the position of state quo to which the contact 84 corresponds.

A partial or total taking off of the brake is obtained by restablishing for a greater or less time the flow of current in the electromagnets 57, giving rise to a more or less complete passage of the liquid from the brakecylinder into the reservoir b. The liquid from the pipe 40 is discharged by the passage 75, and the liquid accumulated behind the plunger 34 comes into the chamber 49 and then goes by the passages 56, 62, and 53 into the chamber 50, whence it returns to the reservoir by the pipe .9.

I declare that what I claim is-- 1. In a hydraulic brake, the combination with the brake-cylinder and reservoir, of a pump having a two-part cylinder, at differential piston reciprocating therein with means for operating the same, a pipe connecting the reservoir with one side of said cylinder, a pipe connection from the same side of said pump-cylinder to the brake-cylinder, a passage connecting said connection with the other side of the pump-cylinder, and suitable valves controlling said connections, substantially as described.

2. In a hydraulic brake, the combination with the brake-cylinder and reservoir, of a pump having a two-part cylinder, a diiferential piston reciprocating therein, oppositelyarranged admission and discharge chambers communicating with the rear end of said pump-cylinder, a pipe connection from said admission-chamber to the reservoir, a pipe connection from the discharge-chamber to the brake-cylinder, a valve controlling the passage from the admission-chamber to the rear end of the pump-cylinder, a valve controlling the passage from said rear end to the dis charge -chamber, and a continuously-open passage from the opposite end of the pump cylinder to said discharge-chamber, substantially as described.

3. In a hydraulic brake, the combination with the brake-cylinder and liquid-reservoir, of a pump having a two-part cylinder, a continuously-operating diiferential piston reciprocating therein, oppositely-arranged admis sion and discharge chambers having passages communicating with the rear end of said pump-cylinder, an open passage from the ad mission-chamber to the opposite end of the pump-cylinder, a pipe connection from said admission-chamber to the reservoir, a pipe connection from the discharge-chamber to the brake-cylinder, a check-valve controlling the passage from said admission chamber, a checkvalve con trolling the passage to the discharge-chamber, means for raising the valve of the admission-chamber, and means whereby said valve maybe caused to raise the valve of the discharge -chamber, substantially as described.

4. In a hydraulic brake, the combination with the brake-cylinder and liquid-reservoir, of a pump having a two-part cylinder, a differential piston continuously operating therein, admission and discharge chambers communicatin g with the rear end thereof, an open passage from the discharge-chamber to the opposite end of the pump-cylinder,checkvalves controlling the passages from said chambers to the rear end of said pump-cylinder, a pipe connection from the admissionchamber to the reservoir, a pipe connection from the discharge-chamber to the brake-cylinder, and a pressure-controlled by-pass between said chambers, substantially as described.

In witness whereof I have hereunto set my hand in presence of two witnesses.

CAMILLE DUREY.

Witnesses:

EDWARD P. MACLEAN, ANDRE MOSTIOKER. 

